Design and characterization of a novel chitosan/nanocrystalline calcium phosphate composite scaffold for bone regeneration

• Published in: Journal of Biomedical Materials Research Part B Vol. 88A; no. 2; pp. 491 - 502
• Main Authors: Chesnutt, Betsy M., Viano, Ann M., Yuan, Youling, Yang, Yunzhi, Guda, Teja, Appleford, Mark R., Ong, Joo L., Haggard, Warren O., Bumgardner, Joel D.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-02-2009
• Subjects: Adsorption; Animals; Biocompatible Materials - chemistry; Biocompatible Materials - metabolism; bone graft; Bone Regeneration; Bone Substitutes - chemistry; Bone Substitutes - metabolism; Calcium Phosphates - chemistry; Calcium Phosphates - metabolism; Cells, Cultured; chitosan; Chitosan - chemistry; Chitosan - metabolism; composite; Compressive Strength; Humans; hydroxyapatite; Materials Testing; Osteoblasts - cytology; Osteoblasts - physiology; Porosity; Proteins - metabolism; Surface Properties; tissue engineering; Tissue Scaffolds
• ISSN: 1549-3296; 1552-4965; 1552-4981
• DOI: 10.1002/jbm.a.31878

To meet the challenge of regenerating bone lost to disease or trauma, biodegradable scaffolds are being investigated as a way to regenerate bone without the need for an auto‐ or allograft. Here, we have developed a novel microsphere‐based chitosan/nanocrystalline calcium phosphate (CaP) composite scaffold and investigated its potential compared to plain chitosan scaffolds to be used as a bone graft substitute. Composite and chitosan scaffolds were prepared by fusing microspheres of 500–900 μm in diameter, and porosity, degradation, compressive strength, and cell growth were examined. Both scaffolds had porosities of 33–35% and pore sizes between 100 and 800 μm. However, composite scaffolds were much rougher and, as a result, had 20 times more surface area/unit mass than chitosan scaffolds. The compressive modulus of hydrated composite scaffolds was significantly higher than chitosan scaffolds (9.29 ± 0.8 MPa vs. 3.26 ± 2.5 MPa), and composite scaffolds were tougher and more flexible than what has been reported for other chitosan‐CaP composites or CaP scaffolds alone. Using X‐ray diffraction, scaffolds were shown to contain partially crystalline hydroxyapatite with a crystallinity of 16.7% ± 6.8% and crystallite size of 128 ± 55 nm. Fibronection adsorption was increased on composite scaffolds, and cell attachment was higher on composite scaffolds after 30 min, although attachment rates were similar after 1 h. Osteoblast proliferation (based on dsDNA measurements) was significantly increased after 1 week of culture. These studies have demonstrated that composite scaffolds have mechanical properties and porosity sufficient to support ingrowth of new bone tissue, and cell attachment and proliferation data indicate composite scaffolds are promising for bone regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009